Friday, June 22, 2007
Biodiversity Corner: Cecropia Moth
At about 8 p.m. Tuesday night June 12, I discovered a creature circling the light in my garage. Its size and flight were similar to a bat's. Its flight had bat-like, erratic changes of direction, but lacked the bat's quick, energetic accelerations. There was no discernible sound. It landed clumsily on the hood of my car, whereupon I could see it was a very large moth. With what appeared to be a large effort, it again took to flight. That guy looks tired, I thought.
The next morning, I found it on the garage wall. It offered no resistance to my handling it and taking it inside for a photo shoot. It had trouble standing on flat surfaces, but was right at home clinging to my finger. The ends of its legs have hooks that allow it to hold on to surfaces that are not completely smooth. It was very pleasant to feel it grasping my finger, and I thought it would make a good pet for someone with a gentle touch (although large, it is quite delicate, evidenced by some tears in its wings).
The adult would in fact probably not make a good pet, as its lifespan is listed as only seven to ten days. The adult moth lives only to mate and lay eggs; it has no mouth parts and therefore cannot feed. This is perhaps to make up for its early life as a caterpillar, which has a voracious appetite and can grow up to five inches long. If you would like to see pictures of the development stages of the moth, check out www.wormspit.com/cecropia.htm. And if you want to raise them yourself, have a look at www.kiva.net/~daylight/moth.html.
During all of Wednesday, my Cecropia was so lethargic I feared it had hit its expiration date, but on Thursday morning, its legs pawed the air excitedly, and it proceeded to lay a small cluster of eggs, thereby ending the debate on its gender.
The female Cecropia uses more than her beauty to attract a mate. At night, she emits chemicals, called pheromones, to get his attention. Males, using their large, feathery antennas as sensors, have been documented to fly as far as seven miles to reach the source of these powerful chemicals. Mating usually begins before dawn and lasts until the foll owing evening! The male then flies off, unable to resist the allure of other pheromone emitters. The female devotes the remainder of her life to laying her eggs, typically on the leaves of trees that are the preferred food of the caterpillars. These include fruit trees, willow and maple.
More facts. Scientific name: Hyalophora cecropia, of the class Insecta, order Lepidoptera (butterflies and moths), family Saturniidae (giant silk moths).
Range: central and eastern U.S. and Canada, excluding Newfoundland.
Size: six-inch wingspan is common; mine measured closer to six and a half inches. It has the broadest wingspan of any North American moth.
Emergence: adults emerge mid-May through early June in the northern part of their range.
© 2007 The Carlisle Mosquito